Method of advancing knitwork during its manufacture

ABSTRACT

A method and apparatus for withdrawing the knitwork from the rotating needle cylinder through a withdrawal tube rotating at a speed substantially equal to it. The tube is provided with a baffle dividing the tube into an axial through passage and a pocket therein for receiving a portion of the knitwork. A vacuum is applied to the pocket to suck the leading end of the knitwork thus doubling the knitwork about the baffle, and allowing the knitwork to rotate about the central axis conjointly with the needle cylinder. At the same time the vacuum is applied to the end of the withdrawal tube to pull the knitwork, thus held at the leading end in the pocket and at the trailing end in the needles, until the knitwork is completed. By selectively releasing the trailing end or the leading end, the knitwork when finished may be withdrawn fully either leading or trailing end first or even in folded condition.

States Pate 1191 1111 3,858,417 Uhlir et al. Jan. 7, 1975 [54] METHOD OF ADVANCING KNITWORK 3,738,123 6/1973 Mazzi .1 66/149 DURING ITS MANUFACTURE 3,745,794 7/1973 Brackett et al. 66/149 S [75] Inventors: 523 gg 'ggggillg both of Primary Examiner-James Kee Chi Attorney, Agent, or Firm-Murray Schaffer [73] Assignee: ELITEX, Zavody textilniho strojirenstvi, generalni reditelstui, Liberec, Czechoslovakia [57] ABSTRACT A method and apparatus for withdrawing the knitwork l22l Filed 2 from the rotating needle cylinder through a with- {21 Appl. No.: 316,005 drawal tube rotating at a speed substantially equal to it. The tube is provided with a baffle dividing the tube into an axial through passage and a pocket therein for [30] Foreign Apphcatmn Pnmy Data receiving a portion of the knitwork. A vacuum is ap- 1971 Czechoslovak plied to the pocket to suck the leading end of the knitwork thus doubling the knitwork about the baffle, and [52] US. Cl. 66/149 S allowing the knitwork to rotate about the Central axis IIBL j i y with needle Cylinder. At the Same i [58] Field of Search 51 M9 153 the vacuum is applied to the end of the withdrawal tube to pull the knitwork, thus held at the leading end [56] References in the pocket and at the trailing end in the needles, UNITED STATES PATENTS 7 until the knitwork is completed. Ely selectively releas 3,036,449 5/1962 Pierre et a1. 66/150 ing the trailing end or the leading end, the knitwork 3,108,462 /1963 Tenconi 66/149 S when finished may be withdrawn fully either leading 3,159,015 12/1964 Moretta... 66/149 S or trailing end first or even in folded condition. 3,550,403 12/1970 Shields 66/150 3,668,900 6/1972 Peet 66/149 5 9 Claims, 2 Drawing Figures [8b 2/ s I9 METHOD OF ADVANCING KNITWORK DURING ITS MANUFACTURE BACKGROUND OF INVENTION The present invention relates to the method and apparatus for withdrawing finished knitwork from circular knitting machines and in particular to a method and apparatus for removing long knitwork pieces without twisting the piece.

In conventional circular knitting machines of either single or double cylinder type, the knitwork is formed on the needles arranged in a rotating needle cylinder and advanced as it elongates through an axially aligned tube which serves both to withdraw and transport the piece to a collecting vessel or central pipeline. The tube is generally placed under pressurized air or vacuum which carries or forces the knitwork pneumatically through the tube.

After completion on the knitting machine the knitwork must be further processed and finished. Generally such additional steps take place on machines remote from the knitting machine itself and it is necessary to arrange the knitwork in a specific orientation to accomplish this object. Orientation is very important when centrialized or common withdrawal apparatus is used. It is also sometimes very important to obtain orientation for a subsequent finishing step that the knitwork must be turned around, end to end.

A device is known for turning knitwork comprising a pair of tubes. The knitwork is drawn through one tube and then over the other tube by means of pressurized air during the knitting operation, and then withdrawn into a collecting vessel. A disadvantage of this device is that without further attachments etc., the knitwork is capable of being withdrawn in only one direction. In general however, all the prior devices result in some twisting and turning of the knitwork during knitting, which create problems in subsequent finishing.

It is the object of the present invention to provide an improved means and method for withdrawing knitwork SUMMARY OF INVENTION According to the present invention the method and apparatus comprises withdrawing the knitwork from the rotating needle cylinder through a withdrawal tube rotating at a speed substantially equal to it. The tube is provided with a baffle dividing the tube into an axial through passage and a pocket therein for receiving a portion of the knitwork. A vacuum is applied to the pocket to suck the leading end of the knitwork thus doubling the knitwork about the baffle, and allowing the knitwork to rotate about the central axis conjointly with the needle cylinder. At the same time the vacuum is applied to the end of the withdrawal tube to pull the knitwork, thus held at the leading end in the pocket and at the trailing end in the needles, until the knitwork is completed. In accordance with the present method, by selectively releasing the trailing end or the leading end, the knitwork when finished may be withdrawn fully either leading or trailing end first or even in folded condition.

The apparatus includes means for rotating the withdrawal tube conjointly with the needle cylinder. Also the tube is journaled in a hollow housing and is provided with perforations in its wall aligned radially with the pocket. The hollow housing being connected to a source of vacuum, and including means for regulating the flow of the air under vacuum. Further the tube is connected to the source of vacuum and also contains means for regulating the flow and means for receiving the knitwork.

Full details of the present invention follow in the subsequent description of the preferred embodiment and will be seen in the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS In the drawings:

FIG. 1 is a vertical sectional view of a circular knit ting machine employing the present invention, showing the needle cylinder, transport tube and withdrawing means taken througn a central axial plane, and

FIG. 2 is an enlarged view of the withdrawing tube showing the pocket.

DESCRIPTION OF THE INVENTION Turning to FIG. 1, the present invention is seen as embodied in a knitting machine of the single cylinder type although as will be obvious, the same may be applied to a double cylinder machine. The needle cylinder 1 as is seen, has a shoulder rotatably seated upon ball bearings 2 set within a groove on the upper surface of the upper flange support 3 of the machine. Extending downwardly through the needle cylinder 1 is an elongated cylindrical conduit 4 fixed at its lower end to the bottom flange 12 of the machine. Fixed by means of one or more screws 5, to the lower end of the cylinder 1 is a coaxial gear 6. The gear 6 rolls against ball bearings 7 set in lower edge of the supporting flange 3, meshing with a pinion gear 8 fixed at the upper end of a vertical shaft 9. The shaft 9 extends downwardly and is journaled at both ends in antifriction bearings 10 set within the upper and lower flange supports 3 and 12. The lower antifriction bearing 10 is held in place by re movable packing 11. A gear wheel 13 is mounted at the lower end of the shaft 9 engaging with an enlarged gear 14 firmly fixed coaxially about a rotatable withdrawing tube 15 which itself is aligned with the axis of the needle cylinder. The gear 14 has a downwardly extending hub which is journaled within the inner race of a radial bearing 16 mounted in a fixed housing 17 which isfastened by screws 18 to the lower surface of the bottom flange support 112. The housing 17 is' an enlarged hollow body substantially cylindrical closed at its upper end by packing which seals about the hub of the gear 14, and at its lower end by packing 18b which seals about a low friction slide ring 19 secured to the exterior of the withdrawing tube 15.

The withdrawing tube 15 is an elongated cylindrical member which as is seen, is axially aligned with the needle cylinder 1. The tube 15 is provided with a plurality of holes 20 (See FIG. 2) axially positioned to open into the hollow space of the housing 17 which is axially arranged to surround the holes 20. The holes 20 are formed in a group in one sector of the wall of the tube and covers an area less than half of the circumference of the tube. The hollow space of the housing 17 is connected by a hose 21 to the suction end of an air pressure fan 22 or similar vacuum device. An adjustable closure flap 23 (such as a butterfly valve) is mounted in the hose 21 and is connected by directed linkage means, solenoid control devices or the like to the control drum of the machine, so that the passage defined by hose 21 between the fan 22 and the hollow housing 17 may be automatically opened or closed in response to the condition and progress of the knitwork.

The withdrawing tube 15 is itself set within an enlarged tubular shroud 24 which is secured at its upper end firmly to the lower side of the housing 17. A hose 25 leads from the lower end of the shroud 24 to a collecting basket 26 which has a perforated upper partition 26a. The lower wall of the basket is closed by a flap 26b while the portion of the basket 26 above the partition 260 is connected by still another hose 27 to the hose 21 leading to the suction end of the fam 22. An adjustable closure flap 28 is mounted within the hose 27, and is also controlled and regulated by connection to the control drum of the machine, in the same manner as is flap 23, and also in response to the progress of the knitwork.

Lastly, there is mounted within the withdrawal tube 15 a baffle 29, which, as is seen in FIG. 2, comprises a substantially semi-circular base member secured at its periphery to the inner wall of the tube 15 above the holes and a flat generally rectangular depending member extending diametrically across the tube 15 and axially in a plane through the axial center of the tube downward below the holes 20.

The baffle 29 divides the tube 15 into a passage between the needle cylinder and the lower hose extending on one side of the baffle and an enclosed pocket 30 formed on the inner side of the baffle. The lower end of the baffle 29 terminates above the lower end of the tube 15 and the lower end of the tube 15 terminates above the juncture of the hose 25 with shroud 24.

In operation, the needle cylinder is operated in conventional manner to knit a knitwork 31, such as an elongated stocking, tubular material or similar article. Flaps 23 and 28 are set, as shown in FIG. 1, in open and closed position respectively to permit fan 22 to suck air in through hose 21, as seen by the full arrow P, but not through hose 27. As the needle cylinder 1 is rotated its motion is transmitted through the gear wheel train to conjointly rotate the withdrawing tube 15. Preferably, the gears 6 and 8 and 13 and 14 conform respectively to each other so that the speed of the tube is equal to that of the cylinder. The knitwork 31 falls through conduit 4 into tube 15 where under action of the vacuum created by fan 22 is sucked into the pocket 30 formed between the baffle 29 and the wall of tube 15 below the holes 20. Knitting continues until such time as the leading end of the knitwork 31 is sucked against the holes 20, at which time the flap 28 is opened allowing the fan 22 to suck air through hose 27 as well as through hose 21. The part of the air flowing through hose 27, seen by the dotted arrow S, withdraws the subsequently knit material beneath the baffle 29 and into the hose 25. At the same time, of course, the leading end of the knitwork 31 is held against the holes 20, and the entire knitwork is rotated about the central axis of needle cylinder 1 and the tube 15.

When the knitwork 31 is completed it is transported into the basket 26, and thence out of the machine via flap 26b by any one of the following variations.

a. Flap 23 is fully closed, then the flap 28 is fully opened and at the same time the knitwork 31 is knocked off the needles of cylinder 1. The suction through hose 27 thus causes the leading edge of the knitwork 31 to be released and be carried through the hose 25 to the gate 261). The knitwork thus is removed leading end first.

b. Flap 23 is fully opened and flap 28 fully closed while the knitwork 31 is knocked off the needles. The knitwork thus is held in pocket 30 until the trailing end of the knitwork falls. Thereafter, by reversing the positions of flaps 23 and 28 to reverse the air flow, the knitwork is turned and transported with its trailing end c. to the basket 26. The flap 28 is fully opened while the flap 23 is closed simultaneously with the knitwork 31 being knocked off the needles. As a result the knitwork is released at both ends simultaneously and is transported into the basket 26 in folded condition with a center section first.

After the knitwork reaches the basket 26 the flaps 23 and 28 may be both closed and the gate 26b opened to allow the knitwork to be withdrawn.

It will be seen from the-foregoing that during the knitting operation the knitwork is folded about the baffle 29 being held by its leading edge in the pocket 30 and its trailing edge on the needles. The two parts of the knitwork is rotated in this position within the rotating tube 15 about the central axis of the needle cylinder and the aligned tube 15 so that no twisting or turning of the knitwork could occur. By selectively choosing the closing of flaps 23 and 28 the knitwork may be withdrawn, leading edge first, trailing edge first, or in folded condition.

The advantage of the present invention lies in the obvious fact that the knitwork is transported from the needle cylinder to the basket 26 and thence from there to the necessary finishing devices in the required condition and is not twisted. As indicated the present invention may be applied to adouble needle cylinder machine and as will be obvious to those skilled in this art to a machine wherein the knitwork is withdrawn in an upward direction. Several machines may be hooked up to a central withdrawal system if desired.

Various other modifications and changes will be obvious to those skilled in the art. Consequently, the present disclosure is intended to be illustrative only of the invention and not limiting thereof.

What is claimed is:

1. A method of pneumatically transporting knitwork upon its manufacture in a circular knitting machine having a rotating needle cylinder on which said knitwork is formed and an open-ended rotating tube axially aligned with said needle cylinder, said tube having an elongated baffle secured to a portion of its inner wall between said cylinder and the open end, said baffle opening toward the open end of said tube to form on one side a pocket and on the other side a passage for the knitwork, comprising the steps of withdrawing said knitwork through the passage in said tube beneath the opening of said pocket, applying suction to said pocket to draw the leading end of said knitwork therein, rotating said tube about its axis at a speed substantially equal to the rotating cylinder and applying suction to the end of said tube to further withdraw the knitwork through said passage while retaining the leading end with said pocket until the trailing end of said knitwork is completed, thereafter knocking off said knitwork from said needle cylinder and releasing said leading end from said pocket and withdrawing the leading or trailing end of the knitwork through the open end of said tube.

2. The method according to claim 1 wherein said knitwork is knocked off said needle cylinder prior to releasing the leading end of said knitwork from said pocket and withdrawing the knocked off end first from said tube.

3. The method according to claim 1 wherein the leading end of said knitwork is released from said pocket prior to the knocking off of said knitwork from the needle cylinder and the leading edge of said knitwork is withdrawn first from said tube.

4. The method according to claim 1 wherein the leading end is released from said pocket simultaneously with the knitwork being knocked off said needle cylinder, and said knitwork is withdrawn from said tube in folded condition with an intermediate portion first.

5. In a circular knitting machine having a needle cylinder on which knitwork is formed, apparatus for withdrawing said knitwork comprising a rotating tube axially aligned with said needle cylinder through which said knitwork is adapted to pass, an elongated baffle located within said tube, said baffle being secured to said duct along its upper and side edge to form a duct for the passage from said needle cylinder of said knitwork on one side thereof and a pocket adapted to receive said knitwork on the opposite side thereof said pocket opening toward the lower end of said tube, means for applying suction to said pocket to draw a portion of sald knitwork therein after movement through said passage, means for applying a suction to the lower end of said tube to draw said knitwork therethrough and means for simultaneously rotating said tube about its axis at a speed equal to that of the needle cylinder.

6. The apparatus according to claim 5 wherein the wall of said tube adjacent said pocket is perforated, said tube being journaled in a hollow housing surrounding said perforations and having a first conduit communicating to a source of suction, said conduit having means for regulating the flow of suction therethrough.

7. The apparatus according to claim 6 including a second conduit extending from said tube communicating with said source of suction, means for regulating the flow of suction therethrough, and a receiving means for said knitwork interposed within said second conduit.

8. The apparatus according to claim 7 including means for selectively actuating the suction regulating means in said first and second conduits.

9. The apparatus according to claim 5 including transmission means connecting said needle cylinder and said tube for conjoint rotation. 

1. A method of pneumatically transporting knitwork upon its manufacture in a circular knitting machine having a rotating needle cylinder on which said knitwork is formed and an open-ended rotating tube axially aligned with said needle cylinder, said tube having an elongated baffle secured to a portion of its inner wall between said cylinder and the open end, said baffle opening toward the open end of said tube to form on one side a pocket and on the other side a passage for the knitwork, comprising the steps of withdrawing said knitwork through the passage in said tube beneath the opening of said pocket, applying suction to said pocket to draw the leading end of said knitwork therein, rotating said tube about its axis at a speed substantially equal to the rotating cylinder and applying suction to the end of said tube to further withdraw the knitwork through said passage while retaining the leading end with said pocket until the trailing end of said knitwork is completed, thereafter knocking off said knitwork from said needle cylinder and releasing said leading end from said pocket and withdrawing the leading or trailing end of the knitwork through the open end of said tube.
 2. The method according to claim 1 wherein said knitwork is knocked off said needle cylinder prior to releasing the leading end of said knitwork from said pocket and withdrawing the knocked off end first from said tube.
 3. The method according to claim 1 wherein the leading end of said knitwork is released from said pocket prior to the knocking off of said knitwork from the needle cylinder and the leading edge of said knitwork is withdrawn first from saiD tube.
 4. The method according to claim 1 wherein the leading end is released from said pocket simultaneously with the knitwork being knocked off said needle cylinder, and said knitwork is withdrawn from said tube in folded condition with an intermediate portion first.
 5. In a circular knitting machine having a needle cylinder on which knitwork is formed, apparatus for withdrawing said knitwork comprising a rotating tube axially aligned with said needle cylinder through which said knitwork is adapted to pass, an elongated baffle located within said tube, said baffle being secured to said duct along its upper and side edge to form a duct for the passage from said needle cylinder of said knitwork on one side thereof and a pocket adapted to receive said knitwork on the opposite side thereof said pocket opening toward the lower end of said tube, means for applying suction to said pocket to draw a portion of saId knitwork therein after movement through said passage, means for applying a suction to the lower end of said tube to draw said knitwork therethrough and means for simultaneously rotating said tube about its axis at a speed equal to that of the needle cylinder.
 6. The apparatus according to claim 5 wherein the wall of said tube adjacent said pocket is perforated, said tube being journaled in a hollow housing surrounding said perforations and having a first conduit communicating to a source of suction, said conduit having means for regulating the flow of suction therethrough.
 7. The apparatus according to claim 6 including a second conduit extending from said tube communicating with said source of suction, means for regulating the flow of suction therethrough, and a receiving means for said knitwork interposed within said second conduit.
 8. The apparatus according to claim 7 including means for selectively actuating the suction regulating means in said first and second conduits.
 9. The apparatus according to claim 5 including transmission means connecting said needle cylinder and said tube for conjoint rotation. 